A question about Q bits

[ZeroZero]

After going round in circles on utube/google I still have no answer to these basic questions. The Net is full of descriptions of Qbits, rather than explanations of Qbits.

If I code a conventional binary computer I can store 1 or 0 (true or false) and can comer back and retrieve it to find the vlaue (e.g. true or false).

If I go to a qubit and find it is in a state of "1 And 0" simultaneously, then how the heck is this useful - being neither one or zero - neither true or  false, or conversely true and false simultaneously?

How does a qbit having three states 0, 1 and "both 0 and 1"  get to be exponentially more powerful?

How is a bit of data stored in a qubit and how is it retrieved? Why is it exponentially more powerful?

Z